Black stuff on rotor

I had my DS front wheel off this weekend and noticed something I haven't seen before. The rotor had a black "smear" (for lack of a better term) about 1/3 in from the outer edge all the way around the rotor. I took a damp rag to see if it wiped off, and nothing came off. It reminds of something that might be "burnt" on there. Does anyone know what I'm looking at here? Problems it might indicate?

You may have gotten (is that a word?) something stuck between the pads and the rotor and it melted to the rotor. You should pull the pads and inspect them to be sure and see if you can get the "smear" off with some mild sandpaper.

was it by any chance on a chrysler or ford? because in my experience of brakes, chryslers and fords rotors glaze very easily. and this is probably what youve got, and if its a chrysler, the newer ones not brand new but newer models had brake pads without the chamfer on the edges and if they did, they were minimal, so they didnt dissapate heat very well, that, combined with non vented rotors, and every chrysler was coming in with glazed pads and rotors.

point being, take your wheel off, if the rotors are glazed (rough with lines) turn them or replace them, then if your pads are still good, sand the center down, then chamfer the edges, and you should be good to go (Y)